IMO the big reason that Boeing is going after BBD is not the CS100, but the prospect of a CS500 which would compete directly with the antiquated 737. Boeing has, for now, left Embraer alone because the E2 can't be stretched as much as the C-series.

The hypocrisy is strong with Boeing though. Boeing's received over $8 billion in tax breaks (errrr subsidies) from the state of Washington alone.

https://www.seattletimes.com/seattle-news/boeings-historic-t...